Refrigeration apparatus



Patented July 25, 1944 REFRIGERATION APPARATUS Robert T. Briuolara, New Dorp,

Staten Island, N. Y.

Application June 12, 1943, Serial No. 490,561

9 Claims. (CL 62-125) This invention relates to refrigeration apparatus and relates more particularly to apparatus utilizing refrigerant vapor for recirculating refrigerant liquid from accumulators used with flooded evaporators located at higher levels, into the evaporators.

In many installations utilizing refrigeration, a central condensing unit is used to supply refrigerant to a number of evaporators at diiferent locations. For greatest economy and best results the evaporators are run flooded. This occasions some carry-over of .liquid refrigerant with the vapor into the suction side of the compressor. This is undersirable and to prevent the carryover of the liquid, an accumulator is placed in the suction line which traps out the liquid. This liquid accumulates and it is necessary to dispose of it. It is preferred to locate the evaporators above the accumulator and the most dependable method of disposing of the liquid inthe. accumulator has been to provide motor actuated pumps for evacuating the accumulator and for returning the liquid to the evaporators or associated receivers.

This invention provides lift fittings utilizin refrigerant vapor for evacuating accumulators and for recirculating the refrigerant from the accumulators to the evaporators..

Objects of the invention are to simplify and to reduce the cost of, and the operating expense of, refrigeration systems.

The invention will now be described with reference to the drawing. of which:

Fig. 1 is an elevation view in section of one embodiment of this'invention applied to a liquid cooler, and

Fig. 2 is an elevation view in section of another embodiment of this invention applied to an air cooler.

Referring first to Fig. 1, the liquid cooling tubes I are located in the evaporator shell I and are interconnected as is conventional for cooling a liquid such for example, as brine. A liquid distributor trough I having the lower nozzles I feeds liquid refrigerant from a conventional condensing unit (not shown) over the surfaces of the tubes.

The unevaporated liquid collects in the bottom of the shell 8 which acts as an accumulator and drains under the static head indicated as it, through the tube 9 into the shell type pilot evaporator IO. The evaporator In contains the tubes ll through which the liquid to be cooled is circulated so that heat may be absorbed for evap-.

crating a portion of the liquid in the pilot evap orator l0.

A mixture of refrigerant. liquid and vapor passes from the evaporator "I through the tube It into the lift fitting I351 The blowing of the vapor due to the static head It and to the evaporation of refrigerant in the evaporator ll causes liquid to be lifted froln'the lower lift fitting l3 through thetube it into the higher located lift fitting ll by entraining the liquid in bubbles which move upwardly through the tube It. This process is repeated in the lift fitting l5 and the tube It with the result liquid is lifted, into the separator or discharge trap l1 and-is recirculated from same through the'tube l8 into thedistributor trough I. v

Any number of lift fittings maybe used depending upon the height to which the liquid is to be lifted.

The jackets I! may be placed around the lift fittings l4 and I5 anda portionof the liquid to be supplied through the tubes 50 and cooled may be circulated through these Jackets-for aiding the lift efiect by evaporating liquid refrigerant in the lift fittings. 1

The float chamber III is connected by the tube II to the condensing unit and receives liquid refrigerant ,therethrough. The upper portion of the chamber is connected by the tube 12 to the shell I above the liquid level to be maintained therein and the lower portion of the chamber is connected by the tube 23 to the shell 5 below the liquid level to be maintained therein. The float 24 regulates the inflow of liquidthrough the tube II for maintaining the proper, liquid level in the chamber 20 .andin the lower or; ac-

- cumulator portion of theshell t.

The fioat chamber thus ensures that the proper liquid level is maintained inI-the accumulator for providing the head It necessaryfor proper operation of the lift fittings. Y

The pipe 25 connects the O with the suction sideof the compressor'forrejtuming the refrigerant vapor theretd Referring now to Fig. '2, the interconnected evaporator tubes 26 are providedwitnthe extended surface fins ll and serve as aforced air cooler. The distribution header 28 connects the uppermost tube It with the condensingunit and supplies liquid refrigerant into the tubes. The lowermost tube connects'with the'suctionheade'r 2!. The liquid drains the tubes 25 and hence develops no liquid head when'fiooding-the tubes.

1 cess liquid W9 th fi fil bs ll intothe accumulato'rjtl' and the liquid-drains interior or shell therefrom through the tube 32 into the pilot evaporator 33. Evaporation takes place in the evaporator 33 and vapor is formed which lifts the refrigerant liquid between bubbles of vapor through the tube 34 into the lift fitting 35. Additional evaporation takes place in the lift fitting 35 and the vapor lifts the liquid refrigerant through the pipe 3' into the lift fitting 31. The process is repeated and the liquid is lifted through the tube 38 and into the lift fitting; 39. Additional lift-fittings could be used if the height the liquid to be lifted iustifies more.

The liquid from the upper lift fitting :9 passes through the tube 40 intothe distribution header The accumulator II is so located with respect to the lowest evaporator tube 28 and the lower end of the pilot evaporator "is so located with I respect to the accumulator that the liquidhead indicated as h on Fig. 2 is provided between the surface of the liquid in the accumulator and in the pilot evaporator.

The vapor actuating the lift fittings is at a pressure h less the sum total height of the bubbles in the lift tubes and hence is positive pressure greater'than the suction pressure.

The float chamber ll is connected by the pipe 42 to the condensing unit for sup lying liquid refrigerant into the float chamber. The upper portion of the. chamber ll is connectedby the pipe ll into the accumulator Ii above'the liquid level therein," The lower portion of the chamber 4i is connected into the lower portion of the accumulator. The float is maintains the proper level in meson chamber for maintaining the desired liquid head h. I v

The upper endv ofthe accumulator ll is connected by the pipe 48 to the suction side of the compressor for returning the vapor thereto.

The lift fittings and the pilot evaporators of Figs. 1 and 2 may be heated by air or by steam or'electricity or by any suitable source of heat for evaporating, sufilcient' liquid refrigerant be understood that the invention is not limited thereon for providing vapor bubbles for, lifting to the exact apparatus and'arrangements of apparatus illustratedas modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is: 1 1. Refrigeration apparatus comprising a main evaporator, means forming a liquid accumulator connected to *said evaporator, said accumulator having a sump locatedbelow said evaporator for draining .liquid therefrom, a pilot evaporator connected to said accumulator for receiving liquid therefrom, and means including a plurality of lift fittings connecting said. pilot evaporator and said main evaporator, said pilot evaporator absorbing heat: and evaporating liquid therein and said lift fitting utilizing said vapor tov lift said pilot evaporator absorbing heat and evaporating liquid therein and said lift fittings utilizing said vapor to lift liquid refrigerant from said pilot evaporator for supply to said main evaporator.

3. Refrigeration apparatus comprising a main evaporator, means forming a liquid accumulator connected to said evaporator, said accumulator having a sump located below said evaporator for draining liquid therefrom, a pilot evaporator connected to said accumulator and receiving liquid therefrom, means including a plurality of lift fittings connecting said pilot evaporator and said main evaporator, and fioat controlled means for supplying liquid refrigerant into said accumulator in addition to that supplied from said main evaporator, said pilot evaporator absorbing heat andevaporating liquid therein and said life fittings utilizing said vapor to lift liquid refrigerant from said pilot evaporator for supply to said main evaporator.

4. Refrigeration apparatus comprising a shell, a plurality of tubes in said shell, means for flowing liquid refrigerant over the outside surfaces of said tubes, the unevaporated liquid collecting in the lower portion of said shell below the lowermost of said tubes, a pilot evaporator connected to the lower portion of said shell for receiving liquid refrigerant therefrom, and means including a plurality of lift fittings connecting said evaporator with said flowing means, said pilot evaporator absorbing heat and evaporating liquid refrigerant therein to form vapor and 'said fittings'utilizing said vapor to lift liquid refrigerant from said pilot evaporator for supply to said flowing means.

5. Refrigeration apparatus comprising a shell, a plurality of tubes in said shell, means for flowing liquid refrigerant over the outside surfaces of said tubes, the unevaporated liquid collecting in the lower portion of said shell below the lowermost of said tubes, a pilot evaporator connected to the lower portion of said shell for receiving liquid refrigerant therefrom, means including a plurality of lift fittings connecting said evaporator with said flowing means, and means for maintaining a predetermined liquid level in said lower portion of said shell, said pilot evaporator-absorbing heat and evaporating liquid refrigerant therein to form vapor and said fittings utilizing said vapor to lift liquid refrigerant from said .pilot evaporator for supply to said flowing means.

6. Refrigeration apparatus comprising a shell, a plurality of tubes in said shell, means for flowing liquid refrigerant over the outside surfaces of said tubes, the unevaporated liquid collecting in the lower portion of said shell below the lowermost of said tubes, a. pilot evaporator connected to the lower portion of said shell for receiving liquid refrigerant from said pilot, evaporator for predetermined liquid level in said accumulator, ll

liquid refrigerant therefrom, means including a plurality of lift fittings connecting said evaporator with said flowing means, and float controlled means for supplying liquid refrigerant into the lower portion of said shell in addition to that supplied by said flowing means, said pilot evaporator absorbing heat and evaporating liquid refrigerant therein to form vapor and said fittings utilizing said vapor to lift liquid refrigerant from said pilot evaporator for supply to said flowing means.

'7. Refrigeration apparatus comprising a plurality of superimposed, interconnected evaporatortubes, means for supplying refrigerant liquid into the uppermost of said tubes, an accumulator having a sump arranged below and connected ,into the uppermost of said tubes, an accumulator having a sump arranged below and connected to the lowermost of said tubes forreceiving liquid therefrom, a pilot evaporator connected to said accumulator for receiving liquid therefrom, means including a plurality of lift fittings connected to said pilot evaporator and to said one tube, and means for maintaining a predetermined liquid level in said accumulator, said pilot evaporator absorbing heat and evaporating liquid refrig erant therein and forming vapor, and said fittings utilizing said vapor to lift liquid from said pilot evaporator for supply to said tubes.

9. Refrigeration apparatus comprising a plurality of superimposed, interconnected evaporator tubes, means for supplying refrigerant liquid into the uppermost of said tubes, an accumulator having a sump arranged below and connected to the lowermost of said tubes for receiving liquid therefrom, a pilot evaporator connected to said accumulator for receiving liquid therefrom, means including a plurality of lift fittings connected to said pilot evaporator and to said one tube, and float controlled means for supplying refrigerant liquid into said accumulator in addition to that supplied fromsaid tubes, said pilot evaporator absorbing heat and evaporating.

liquid refrigerant therein and forming vapor, and

said fittings utilizing said vapor to lift liquid from said pilot evaporator for supply to the uppermost of said tubes.

ROBERT T. BRIZZOLARA. 

